Influence of purified multiwalled carbon nanotubes on the mechanical and morphological behavior in poly (L-lactic acid) matrix

Author(s)

Leal, C. V. ^[1] ; Martinez, D. S. T. ^{[2, 3]} ; Mas, B. A. ^[4] ; Alves, O. L. ^[2] ; Duek, E. A. R. ^{[4, 1]}

Affiliation

^[1] Univ Estadual Campinas, Fac Mech Engn, Dept Mat Engn, BR-13083860 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Inst Chem, Solid State Chem Lab, POB 6154, BR-13081970 Campinas, SP - Brazil

^[3] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Nanotechnol Natl Lab LNNano, BR-1308970 Campinas, SP - Brazil

^[4] Pontifical Catholic Univ Sao Paulo PUCSP, Fac Med Sci, BR-18030095 Sorocaba, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS; v. 59, p. 547-560, JUN 2016.
• Web of Science Citations: 5

Abstract

Poly (L-latic acid) (PLLA) is a bioresorbable polymer widely used as a biomaterial, but its fragility can limit its use. An alternative is to produce polymer nanocomposites, which can enhance the mechanical properties of polymeric matrix, resulting in a material with differentiated properties. In this work, PLLA based nanocomposites containing 0.25, 0.5 and 1.0 wt% of purified multiwalled carbon nanotubes (p-MWCNTs) were prepared by the solvent casting method. The morphology and mechanical properties results show an improvement in strain at break for 0.25 and 0.5 wt% p-MWCNTs and an increase in stiffness and elastic modulus for all compositions. Nanocomposites presented a p-MWCNTs agglomeration; however, there was a good stress transfer between PLLA and p-MWCNTs, which was confirmed by the increase in the hardness and elastic modulus. Atomic force microscopy analysis indicated an increase in roughness after nanotube addition. The in vitro biological study showed that PLLA/p-MWCNTs nanocomposites are cytocompatible with osteoblasts cells. The capacity of PLLA nanocomposites to stimulate osteogenesis was investigated by alkaline phosphatase (ALP) activity assay. Higher ALP activity was found on osteoblasts cultured on nanocomposites with 0.25 and 0.5 wt% p-MWCNT compared to neat PLLA, confirming that PLLA cytocompatibility was improved on these compositions. Finally, our results showed that by a simple and inexpensive solvent casting method, it is possible to manufacture biofunctional nanocomposites devices with potential for orthopedic applications. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 08/57867-8 - National Institute for Research, Development and Innovation in Functional Complex Materials
• Grantee: Fernando Galembeck
• Support Opportunities: Research Projects - Thematic Grants